About Running Pace & Race Time Predictor
Predict finish times and required paces across 5K, 10K, Half Marathon (21.1 km), and Full Marathon (42.2 km) based on a recent benchmark race time using Peter Riegel's physiological endurance formula.
Key Capabilities & Features
- Peter Riegel endurance formula (T2 = T1 × (D2 / D1)^1.06) predicting multi-distance finish times
- Generates predicted finish times and required paces (min/km and min/mile) for 5K, 10K, Half Marathon, and Marathon
- Supports custom benchmark race distances and times
- One-click export of complete race prediction table
How to Use Running Pace & Race Time Predictor
Choose Benchmark Race
Select a race distance you have recently completed (e.g. 5K or 10K).
Enter Finish Time
Input your actual chip finish time.
Review Predictions
Examine predicted times and target pacing for longer distances.
Privacy & In-Browser Execution Guarantee
100% client-side calculation. Your data never leaves your browser.
Frequently Asked Questions
What is Peter Riegel's formula?
Developed in 1977 by research engineer Peter Riegel, T2 = T1 × (D2 / D1)^1.06 models cardiovascular endurance decay over distance and is utilized by major athletic organizations worldwide.
Does the formula assume proper endurance training?
Yes. The Riegel formula assumes the athlete has completed aerobic mileage and long runs appropriate for the target distance.